python/iot3: extend OpenTelemetry attributes

[ymorin-orange]

Features;

• Extend OpenTelemetry attributes
  • common, generic attribute iot3.core.sdk_language
  • MQTT attributes iot3.core.mqtt.payload_size and iot3.core.mqtt.topic

---

How to test

1. Prepare an OpenTelemetry collector on localhost:

   $ docker container run \
       --rm \
       -p 16686:16686 \
       -p 4318:4318 \
       jaegertracing/all-in-one:1.58
   

   then open a browser on the Jaegger UI:

   http://localhost:16686/
   

2. Start an MQTT client:

   $ mosquitto_sub \
       -h test.mosquitto.org -p 1883 \
       -t 'test/+/iot3/#' \
       -F '%j' \
   | jq -C .
   

3. Test IoT3 Core SDK:
   1. start an environment with python 3.11:

      $ docker container run \
          --rm \
          -ti \
          --network host \
          -e http_proxy \
          -e https_proxy \
          -e no_proxy \
          --user $(id -u):$(id -u) \
          --mount type=bind,source=$(pwd),destination=$(pwd) \
          --workdir $(pwd) \
          --entrypoint /bin/bash \
          python:3.11.9-slim-bookworm

   2. create a /venv/ in a writable location, and activate it:

      (docker) python3 -m venv /tmp/iot3
      (docker) . /tmp/iot3/bin/activate

   3. install the IoT3 Core SDK (notice the trailing dot .):

      (docker) pip3 --disable-pip-version-check install .

   4. Run the OpenTelemetry-only test:

      (docker) ./tests/test-iot3-core-otel

      then, in Jaegger, search for the traces for the test-service service.
   5. Run the MQTT with OpenTelemetry test:

      (docker) ./tests/test-iot3-core-all

      then, in Jaegger, search for the traces for the test-service service.
   6. Run the simple API test:

      (docker) ./tests/test-iot3-core

      then, in Jaegger, search for the traces for the my-service service.

---

Expected results:

1. The Jaegger UI is displayed in your browser
2. The mosquitto lient is running
3. The IoT3 Core SDK works;
   1. the docker container runs
   2. the python /venv/ is created and activated
   3. the IoT3 Core SDK is installed
   4. the Jaegger UI finds two traces:
      • one with 6 spans, of which the last one is in error, reporting /Some failure/
      • one with a single span, which has a link to the root span of the first trace, above
      • all spans have an attribute:
        • iot3.core.sdk_language=python
   5. the MQTT message is dumped by /mosquitto_sub/:

      {
        "tst": "2024-10-21T08:58:15.206188Z+0200",
        "topic": "test/5c2a8ef897cf0abb1941cea0fd184b7e/iot3/passed",
        "qos": 0,
        "retain": 0,
        "payloadlen": 6,
        "properties": {
          "user-properties": {
            "traceparent": "00-9c39cc87f7098ec82542cdf38617cef9-f8b69d89c0029e03-00"
          }
        },
        "payload": "passed"
      }

      then Jaegger UI finds three new traces, all with a single span:
      • the first is for the failed publish, and has a span:
        • of kind producer
        • with attributes:
          • iot3.core.sdk_language=python
          • iot3.core.mqtt.payload_size=7
          • iot3.core.mqtt.topic=foo/bar/dropped
        • with an error status reporting /The client is not currently connected./
      • the second is for the sucessful publish, and has a span:
        • of kind producer
        • with attributes:
          • iot3.core.sdk_language=python
          • iot3.core.mqtt.payload_size=6
          • iot3.core.mqtt.topic=foo/bar/passed
        • with an unset status
      • the third is for the receive, and has a span:
        • of kind consumer
        • with attributes:
          • iot3.core.sdk_language=python
          • iot3.core.mqtt.payload_size=6
          • iot3.core.mqtt.topic=foo/bar/passed
        • with an unset status
        • with a link to the span of the second trace, above
   6. the results are similar to those of step 5, above